BL 6 inch Mk XXIII naval gun
|wars=Second World War Korean War |designer= |design_date= |manufacturer= |production_date= |number=469Campbell 1985 pp.34-36 |unit_cost= |variants= |weight=7 tonnes |length= |part_length=300 inches (7.6 meters) |width= |height= |crew= |cartridge= |caliber= |action= |rate= |velocity=2760 feet per second (840 m/s) |range= |max_range= at 45 degrees elevation |feed= |sights= |breech= |recoil= |carriage= |elevation= |traverse= }} The 50 calibre 'BL 6 inch gun Mark XXIII'Mark XXIII = Mark 23. Britain used Roman numerals to denote Marks (models) of ordnance until after World War II. Mark XXIII indicates this was the twenty-third model of BL 6-inch gun. was the main battery gun used on the Royal Navy and British Commonwealth's conventional (non-anti-aircraft) light cruisers built from 1930 through the Second World War, and passed into service with several other navies when ships were disposed of after the end of the War. Description ]] , 2006]] It replaced the BL 8 inch Mk VIII naval gun used on earlier Washington Naval Treaty cruisers. These built-up guns consisted of a tube and 4.5 metre jacket with a hand-operated Welin breech block. Cloth bags contained 14 kg (30 pound) charges of cordite or flashless (NQFP) powder for a 51-kg (112-pound) projectile. Useful life expectancy was 1100 effective full charges (EFC) with standard cordite and 2200 EFC with NQFP per barrel. The typical maximum rate of fire was eight rounds per gun, per minute.[http://www.hnsa.org/doc/pdf/ou6359a.pdf O.U. 6359A, Handbook for 6-Inch, B.L., Mark XXIII Guns on Triple, Mark XXII Mounting, 1937], page 8. The Mk XXIII turret design was improved through a "long trunk" ammunition hoist, which reduced the crew requirements and increased the speed of the ammunition hoists. As in the MK XXII turret loading could be accomplished at any angle up to 12.5 degrees gun elevation.Campbell, Naval Weapons of WWII, p.35-36. A RN gunnery officer on HMS Bermuda gave details of the loading cycle which could be attained in the Mk XXIII turret with a well trained crew: "...a loading cycle of four and a half to 5 seconds was attained at low elevation, another two to three seconds being required with the guns elevated for long range. The time would lengthen as fatigue set in, but was creditable..." Brooke, p.200 Ships mounting BL 6 inch Mk XXIII guns Shell trajectory Ammunition File:HMS Belfast - Gun turret - Shells and tools.jpg| S.A.P. shells (left), cordite cartridge (lower right) and cartridge container (centre right) on HMS Belfast Weapons of comparable role, performance and era * 15 cm SK C/25 : German equivalent light cruiser gun, operating at higher velocity * 15.5 cm/60 3rd Year Type : slightly larger Japanese equivalent * 6 inch 47 caliber : US equivalent light cruiser gun Surviving examples * Y turret from HMNZS Achilles (70) is preserved at the entrance to Devonport Naval Base, Auckland, New Zealand * Guns and turrets are preserved on museum ship HMS Belfast (C35) in London, UK Notes and references Bibliography * * * External links *Tony DiGiulian, Britain 6"/50 (15.2 cm) BL Mark XXIII Category:Naval guns of the United Kingdom Category:152 mm artillery Category:World War II naval weapons of the United Kingdom